We are an innovative media company serving the greater good of our communities - through empowering stories, impactful investigations and extensive marketing services. With 49 television stations and two radio stations in 41 U.S. markets, we are the largest owner of big four network affiliates in the top 25 markets, reaching approximately one-third of all television households nationwide. Each television station also has a robust digital presence across online, mobile and social platforms, reaching consumers whenever, wherever they are. Each month, we reach 50 million consumers on-air and approximately 35 million across our digital platforms. We have been consistently honored with the industry's top awards, including Edward R. Murrow, George Polk, Alfred I. DuPont and Emmy Awards. Through TEGNA Marketing Solutions (TMS), our integrated sales and back-end fulfillment operations, we deliver results for advertisers across television, email, social, and Over the Top (OTT) platforms, including Premion, our OTT advertising network.
All of this is now delivered through a company with one singular focus; in 2017, we completed our transformation into a pure-play broadcast company. On May 31, 2017 we successfully completed the spin-off of Cars.com into a separate stand-alone public company and on July 31, 2017, we completed the sale of our controlling ownership interest in CareerBuilder. The completion of these strategic actions has reduced our debt and has further strengthened our balance sheet, providing us the ability to invest in our media businesses, capitalizing on opportunities for organic and acquisition-related growth. Our media operations generate strong and dependable cash flows and we are financially disciplined, which allows us to return additional value to shareholders through dividends and share repurchases. We are a leader in embracing change and driving innovation across our businesses, and we are well-positioned to benefit from the evolving regulatory environment.
We have one operating and reportable segment which generated revenues of $2.2 billion in 2018. The primary sources of our revenues are: 1) advertising & marketing services revenues, which include local and national non-political advertising, digital marketing services (including Premion), and advertising on the stations' websites and tablet and mobile products; 2) subscription revenues, reflecting fees paid by satellite, cable, OTT (companies that deliver video content to consumers over the Internet) and telecommunications providers to carry our television signals on their systems; 3) political advertising revenues, which are driven by even year election cycles at the local and national level (e.g. 2018, 2016) and particularly in the second half of those years; and 4) other services, such as production of programming from third parties and production of advertising material.